[ClusterLabs Developers] bug? in heartbeat/LVM OCF script

[Vladislav Bogdanov]

21.06.2016 20:03, Chris Friesen wrot:
> On 06/20/2016 05:50 PM, Chris Friesen wrote:
>>
>> Hi,
>>
>> The heartbeat/LVM OCF script uses the following logic for the LVM_status() routine:
>>
>> if [ -d /dev/$1 ]; then
>>      test "`cd /dev/$1 && ls`" != ""
>>      rc=$?
>>      if [ $rc -ne 0 ]; then
>>          ocf_exit_reason "VG $1 with no logical volumes is not supported by this RA!"
>>      fi
>> fi
>
> <snip>
>
>> I think it would be better to query the activity directly, using something like
>> "lvs -o name,selected  -S lv_active=active,vg_name=<volume_group>"
>
> I'm testing with the following code instead of the above snippet and it seems to work okay:
>
>         # Ask lvm whether the volume group is active.  This maps to
>         # the question "Are there any logical volumes that are active in
>         # the specified volume group?".
>         lvs --noheadings -o selected  -S lv_active=active,vg_name=${1}|grep -q 1

This ^^^ has a big chance to timeout in both monitor and subsequent stop 
operations if clustered VG is used and clvmd is stuck because dlm is 
waiting for fencing (of another node) to finish.
Or if (clustered) VG is created on an iSCSI/iSRP/FC/FCoE/etc block 
device which is not available for some period of time due to 
target/network problems.

Both cases lead to fencing of all cluster nodes.

>         if [ $? -ne 0 ]; then
>                 ocf_log $loglevel "LVM Volume $1 is not available (stopped)"
>                 rc=$OCF_NOT_RUNNING
>         else
>                 rc=0
>                 case $(get_vg_mode) in
>                 1) # exclusive with tagging.
>                         # If vg is running, make sure the correct tag is present. Otherwise we
>                         # can not guarantee exclusive activation.
>                         if ! check_tags; then
>
>
> The alternative would be to leave the original snippet and add this test if the directory
> is present.
>
> Chris
>
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